Commentary on developments in the endless dispute between evolution and creationism.

Sunday, March 27, 2005

Litmus Tests

The current issue of The Weekly Standard contains this astonishingly bad article by Paul McHugh on the subject of evolution. The Standard is about as mainstream a conservative publication as one is likely to find. That they would publish this sleazy and dishonest article is one more piece of evidence that modern conservatism is anti-science to the core.

I often tell people that they do not need to know much about science to know when they are reading the work of a hack. Immersing myself in anti-evolutionary literature for the last several years has allowed me to develop certian litmus tests that tell me the sort of person I'm dealing with. By this I mean there are certain phrases and arguments that are routine among evolution's critics, but which never appear in the work of more serious commentators. McHugh hits nearly all of them.

Litmus Test One: References to thought control.

Here's McHugh's opening paragraph:

EIGHTY YEARS AGO THIS SUMMER, the Scopes trial upheld the effort of the state of Tennessee to exclude the teaching of Darwinian evolution from Tennessee classrooms. The state claimed Darwinism contradicted orthodox religion. But times change, and recently a federal judge ruled that a three-sentence sticker stating that “evolution is a theory not a fact” must be removed from Georgia high school biology texts because it contradicts orthodox science and represents an unconstitutional endorsement of religion. Both legal mandates--no Darwin yesterday, nothing but Darwin today--look less like science than exercises in thought control.

This is rather like saying, “Both legal mandates--no Copernicus yesterday, nothing but Copernicus today look less like science than exercises in thought control.” Serious people recognize that the issue is teaching accurate scientific information to our students. If that information is entirely on the side of evolution and against its critics (as it is), then that is what should be taught. Nonserious people like McHugh prefer to make their points via incendiary catchphrases like “thought control.”

Incidentally, the sticker McHugh is referring to here was not objectionable primarily because it described evolution as a theory not a fact. The main problems were its singling out evolution for special treatment, presenting a childish version of what the words “fact” and “theory” actually mean, wrongly describing evolution as a theory about the origin of living things, which it is not. I won't rehash the sticker dispute here, however.

Litmus Test Two: Bringing up Inherit the Wind.

Here's McHugh's second paragraph:

Everyone agrees that the Scopes trial (viciously caricatured in the play and movie Inherit the Wind) was a setback for the teaching of scientific reasoning. But the same is true of the Georgia ruling, Darwinism being quite obviously a biological theory and open to dispute. To claim otherwise is to be woefully misinformed.

Serious people do not learn their history from Hollywood. Inherit the Wind was never intended to tell the history of the Scopes trial. Instead, the point was to use the Scopes trial as a metaphor for McCarthyism. The only reason for bringing it up here is to provoke a knowing smile from the Standard's readers. Ah yes, they think, Hollywood is always looking for an excuse to bash traditional values...

And McHugh once again pretends that the sitcker was objectionable because it asserted that evolution was a theory.

Science, as high school students need to know, is a logically articulated structure of beliefs about nature that are justified by methods of reasoning one can evaluate. It is whether the methods pass muster that counts for or against a scientific opinion, not how the opinion fits our preconceptions.

That's a rather odd definition of science, but it's the last sentence that caught my eye. Critics of evolution love to present themselves as courageous free-thinkers, doggedly following the evidence wherever it leads. Unlike those dogmatic, elitist, mainstream scientists, of course.

Litmus Test Four: Pretend that evolutionary biology has made no progress since Darwin.

Here is McHugh's fourth paragraph:

Charles Darwin proposed that random variation within life forms, working together with natural selection (“the preservation of favorable variations and the rejection of injurious variations”) across the vast expanse of time since the earth was formed, explains “how the universe created intelligence,” as Francis Bacon had stated the problem a few centuries before. To judge whether the matter is now closed to all criticism, such that Darwinism stands with scientific facts like “the earth is a planet of the sun” or “the blood circulates in the body,” demands we consider Darwin's method of reasoning.

A serious person would consider it more relevant to consider the methods of reasoning used by modern biologists, not the reasoning of those writing 150 years ago. The methods used by Darwin to investigate nature hold up very well, but the fact remains that modern evolutionary theory is a very different creature than what Darwin proposed. No modern biologist, for example, would pretend that natural selection of random variations is the sole weapon in evolution's arsenal.

McHugh commits this error again later in the article:

DARWIN HIMSELF UNDERSTOOD that questions raised about his narrative had substance. In Chapter IX of On the Origin of Species, he noted that the fossil record had failed to “reveal any . . . finely graduated organic chain” linking, as he proposed, existing species to predecessors. He called the record “imperfect” and went so far as to say, “This, perhaps, is the most obvious and gravest objection which can be urged against my theory.” Darwin presumed that the problem rested on the “poorness of our palaeontological collections” and would be answered when more of “the surface of the earth has been geologically explored.”

Darwin did indeed write those things, but so what? No modern paleontologist would endorse the idea that we have no good examples of transitional series in the fossil record. Nor would any modern paleontologist endorse the idea that finely graduated fossil series are necessarily the expected oucome of Darwin's theories. The fact is that Darwin was writing at a time when little was known about the age of the Earth, the methods of fossilization, or the mechanisms of speciation. So, on this point, he got it wrong. This was one of the main points of punctuated equilibrium, which McHugh refers to later but shows no evidence of understanding. See Litmus Test Eight.

Litmus Test Five: Misleading use of quotations.

Here are McHugh's fifth and sixth paragraphs:

The leading Darwinist in America, Ernst Mayr, describes the method:

Evolutionary biology, in contrast with physics and chemistry, is a historical science--the evolutionist attempts to explain events and processes that have already taken place. Laws and experiments are inappropriate techniques for the explication of such events and processes. Instead one constructs a historical narrative, consisting of a tentative reconstruction of the particular scenario that led to the events one is trying to explain.

Darwin, Mayr goes on, “established a philosophy of biology . . . by showing that theories in evolutionary biology are based on concepts rather than laws.”

After noting Mayr's fearless use of the words “tentative,” “philosophy,” and “theory,” one surely is justified in responding: No wonder Darwinism, in contrast to other scientific theories, seems an argument without end! It's history--indeed, history captured by that creative-writing-class concept narrative. If historical narrative--and the “philosophy” it propounds--are what justify the Darwinian opinions, the textbook writers of Georgia can legitimately claim that Darwin's “tentative reconstruction” is not only a theory but a special kind of theory, one lacking the telling and persuasive power that theories built on hypothesis-generated experiment and public prediction can garner.

Behold the workings of the anti-evolutionist mind. Here is Mayr, a prominent biologist, using the term “philosophy” while describing evolution, therefore evolution is just a collection of unsupported guesses about natural history.

McHugh apparently found it too much trouble to tell us the source of this quote. It is from a July 200 article in Scientific American. This article was entitled “Darwin's Influence on Modern Thought” and had nothing at all to do with the sort of evidence biologists use to justify their claims about natural history. Instead it addressed the ways in which Darwin changed the way people look at nature and science.

As is painfully obvious to anyone who read Mayr's article, he was not saying that the construction of historical narratives is the end of the process. Rather, it is the beginning. For example, picking up where McHugh left off, we find Mayr writing the following:

For example, three different scenarios have been proposed for the sudden extinction of the dinosaurs at the end of the Cretaceuos: a devastating epidemic; a catastrophic change of climate; and the impact of an asteroid, known as the Alvarez theory. The first two narratives were ultimately refuted by evidence incompatible with them. All the known facts, however, fit the Alvarez theory, which is now widely accepted.

So obviously Mayr believed that competing historical narratives had to be tested against the available evidence. His point was that unravelling history was a new project for science, and one different from the sorts of problems physicists and chemists were dealing with at the time. Experiments are certianly helpful in illuminating possibilities, but they don't directly help us unravel the past. And such laws as exist in biology are statistical in nature, unlike the sorts of laws invoked by physicists.

How typical. How boring. An anti-evolutionist ripping a quotation from its proper context to make it appear to say something it does not.

McHugh is so fond of this tactic, however, that he does it again later in the article:

If Michael J. Behe, the cellular biochemist who wrote Darwin's Black Box, proposes that the complicated molecular mechanisms sustaining the integrity of the cell seem impossible to explain as the result of random variations, the president of the National Academy of Sciences counters by pronouncing, “Modern scientific views of the molecular organization of life are entirely consistent with spontaneous variation and natural selection driving a powerful evolutionary process.” That is, he affirms the Darwinian narrative by restating it, not by offering compelling proof that it is true.

Where, exactly, did Alberts say this? Was it in the course of a lengthy essay intended to refute Behe's claims? No. It was in a very short letter to the editor of the New York Times, and the letter was written in response to an article in which Behe had given a very misleading impression of something Alberts' had written previously. Since Alberts only had about two paragraphs to make his point, he simply stated for the record that Behe's hand-wringing about the formation of complex systems was unwarranted.

Of course, plenty of biologists have responded to Behe in the most direct way imaginable: By showing how the available evidence shows that not only is evolution in principle capable of crafting “irreducibly complex” systems, but also that it is has almost certainly done so in fact. You can find more on this topic here.

Unlike Alberts, McHugh had plenty of space in which to deal with the actual evidence biologists have produced to refute Behe's claims. Rather than refute any of it (an impossible task) he blatantly misrepresents a statement from Bruce Alberts, confident that his sympathetic readers won't bother to check him out.

Litmus Test Six: Bringing up Piltdown man.

In the course of a discussion about the alleged inadequacy of the fossil record (a discussion which could serve as yet another litmus test), McHugh smugly whips out the following:

This imperfection of the historical record was, after all, sufficiently embarrassing to provoke some evolutionary biologists nearly 100 years ago to try to improve on the record by manufacturing the counterfeit fossil Piltdown Man.

Of course, McHugh is simply inventing out of whole cloth the idea that Piltdown Man was an attempt to beef up an inadequate fossil record. The motivation for the hoax had far more to do with national pride (France and Germany had already coughed up hominid fossils by 1912 (the date of the first Piltdown “find”), but England had not). Many people at the time were skeptical of its legitimacy. The only reason it lasted as long as it did were that the scientists of the day lacked reliable dating methods, and that paleontology was not viewed as a serious science at that time. Simply put, no one much cared about Piltdown man.

And it was evolutionary biologists who were prompted to revisit the Piltdown finds many years later, when subsequent fossil finds made it clear that the Piltdown fossils were a square peg in a round hole. For everything you ever wanted to know about Piltdown man, click here.

Today the fossil lineage of humans is among the best documented in the fossil record, with literally more than two dozen distinct species known, each in its correct place in the timeline from an evolutionary standpoint. McHugh can't discuss that, however, since it would obviously destroy his pretentions about the inadequacy of the fossil record. So instead he chums the waters by bringing up the Piltdown hoax, and then seals the deal by lying about its motivations.

Even among committed Darwinists, the imperfection of the fossil record has been a source of huge argument. The Darwinian fundamentalist Richard Dawkins of Oxford believes in smooth and gradual evolutionary processes. He became a vicious antagonist to Stephen Jay Gould of Harvard, who championed “punctuated equilibrium,” with abrupt species generation after millennia of stability. Dawkins attacked Gould in large part because Gould's idea greatly shortened the time evolutionary processes had to generate species.

It was Stephen Jay Gould who first coined the term “Darwinian fundamentalist” for people like Richard Dawkins and Daniel Dennett. It was a ridiculous description when Gould used it, but he at least had some scientific credibility on the subject. He also had specific objections to things Dawkins and Dennett had written, and was trying to actually move the science forward.

When someone like McHugh uses the phrase, however, it is strictly to use the loaded term “fundamentalist” in his description of prominent scientists. This is another device by which the McHugh's of the world can present themselves as the clear-thinking everyman standing up to dogmatic orthodoxy.

I'm sure it will come as news to Dawkins that his objections to punctuated equilibrium (PE) had to do with the fact that PE shortened the time for species generation. In reality, Dawkins' main objection to PE was simply that it was not as important as Gould and Eldredge thought it was. Consider:

What needs to be said now, loud and clear, is the truth: that the theory of punctuated equilibirum lies firmly within the Neo-Darwinian synthesis. It always did. It will take time to undo the damage wrought by the overblown rhetoric, but it will be undone. The theory of punctuated equilibrium will come to be seen in proportion, as an interesting but minor wrinkle on the surface of Neo-Darwinian theory. (Richard Dawkins, The Blind Watchmaker, Page 251).

That hardly sounds like someone who sees PE as some sort of threat to his own treasured view of natural history. Once again we have caught McHugh making stuff up.

On the other side of the coin, Gould and Eldredge also believed in smooth, gradual evolutionary processes. They were completely unambiguous that PE had nothing to do with the mechanisms of evolution. The punctuations in their theory were only sudden on geological time scales; they were still periods of tens of thousands or hundreds of thousands of years.

To put it another way, Gould, Eldredge, Dawkins and everyone else believes evolutionary mechanisms are usually slow and gradual in the sense that that you do not have large-scale changes in the gene pool of a species in one generation. Gould and Eldredge believed, however, that the periods of time during which significant evolutionary change accumulated in a species' gene pool was short relative to the longer periods of time during which the gene pool remained relatively static. Dawkins had no particular objection to that idea, but saw it as an unimportant wrinkle on traditional Darwinism.

Furthermore, Gould frequently pointed out that to find a finely graduated series of transitional forms in the fossil record would imply steady, directional selection maintained for hundreds of thousands of years at a time. That is why Darwin was wrong to think that finely graduated fossil series were the logical expectation of his theory. In reality, PE was an attempt to integrate the allopatric model of speciation into paleontology. I'm sure McHugh does not care about such things, but if you do you can read more about it here.

Litmus Test Nine: Putting words into the mouths of scientists, without providing citations.

But not everyone agreed with this conclusion. Many criticized the Darwinists for extrapolating too far, and now the Darwinists confess that actual, observable variation--whether in the barnyard or in nature--demonstrates only the capacity of a species population to vary within limits.

McHugh writes about “the Darwinists” the way sports writers write about “the Lakers.” If McHugh has a specific statement from a specific person in mind, let him present it and we can discuss the matter. But an accusation this vague can not even be responded to.

Litmus Test Ten: Accusations of dishonesty by scientists.

No farmer or experimental scientist has ever produced a new species by cultivating variations. The peppered moth didn't become a butterfly, and the closely and repeatedly studied fruit fly, despite gazillions of generations producing varieties in the laboratory, always remains a fruit fly. Again, Darwin himself was more honest than his followers have been. He knew the distinction between variations that could be observed and those posited according to the theoretical extrapolation that was key to his narrative.

Of course, Darwin was writing at a time when nothing was known about the nature of inheritance. He devotes a lot of space in The Origin to showing that organisms could vary in more than just trivial and superficial ways. That was controversial at the time. Since he had no knowledge of where variations came from, he had to be more circumspect in his conclusions.

Nowadays we know that ultimately every aspect of an animal's anatomy is under the control of its genes. In principle, any aspect of that anatomy can be affected by changes in the genome. The variations that biologists hypothesize to explain events in the distant past are based on precisely the mechanisms that are known to be operating today.

As for no farmer or experimental scientist ever producing a new species, surely you're kidding Pops!. Having a new species arise by purely natural means isn't even news anymore. This is yet another example of McHugh making stuff up.

McHugh drones on for quite a bit longer, but surely the point is made. Every time I start thinking that maybe anti-evolutionists are serious folks who have actually given some thought to the matter, someone like McHugh comes along to prove me wrong. They really are just a bunch of ignorant, dishonest hacks. It is ironic that McHugh would accuse scientists of being too enamored of their historical narratives. Anti-evolutionism in general, and his article in particular, is all about telling stories. Specifically, it is about telling the story in which dogmatic, anti-religion scientists try to use their awesome power to smite any clear-thinking common man who dares attempt an honest assessment of the evidence. Facts, logic, science, honesty, basic journalistic integrity and sound argumentation all take a back seat to pushing that story.

8 Comments:

The implications of "applying allopatric speciation to the fossil record" is more than a mere wrinkle, as Dawkins would have us believe. There are major genuine disagreements with PE and ND. Donald Prothero notes two such areas of friction:

"The discovery of stasis in most species for millions of years was an fact that biologists did not expect (as even Mayr, 1992, concedes). At first, they dismissed it as genetic homeostasis or stabilizing selection (Charlesworth et al., 1983; Levinton, 1983; Lande, 1985). But such models are only appropriate on scales of a few generations, or at most a few thousand years. No environment is so constant that stabilizing selection can act for millions of years. This type of explanation is typical of reductionist evolutionary genetics (e.g., Dawkins, 1976), which treats organisms as conduits for genes, and even defines evolution as "change in gene frequencies through time." As Mayr (1992) points out, such reductionism is now slowly going out of vogue, as biologists realize that organisms are integrated wholes, with many different genes interacting in complex ways.

More impressive are demonstrations of species stability in spite of well documented environmental change. The fluctuations of glacial-interglacial cycles during the last three million years of the Ice Ages are about as extreme a climactic change as our planet experiences. Yet studies from land mammals (White and Harris, 1977; Barnosky, 1987) to microscopic marine ostracodes (Cronin, 1985, 1987) document extreme stability in most species in spite of these changes. Rather than adapt to new environments, species migrate back and forth in response to them."

and...

"The other major implication of the idea that species are static for millions of years is the implication for the reality of species. Traditionally, species were considered the sum of all their component populations, and all processes (such as selection) operated on the level of individual and populations. But if species are not just arbitrary slices of a continuum, but distinct entities with their own history of "birth" (speciation) and "death" (extinction), then perhaps species have characteristics that operate on a hierarchical level above that of the genes, the individual, or the population. This concept of hierarchy (species are made up of populations, populations are made of up individuals, individuals are made up of genes, etc.) has important implications for evolutionary biology (Gould and Eldredge, 1977; Gould, 1982a, 1982b; Vrba and Eldredge, 1984; Salthe, 1985; Eldredge, 1985b; Gould, 1985; Vrba and Gould, 1986)."

Niles Eldredge goes several steps further to show how different the pluralists are from the neo-darwinists in his book Reinventing Darwin. Gould may have overblown it, but Dawkins has over-trivialized it. Between these two extremes lie a golden medium, a reformulation of the current synthesis that integrates both and includes other established and emerging fields, such as evo-devo. Maybe it's biology's next holy grail.

'Science, as high school students need to know, is a logically articulated structure of beliefs about nature that are justified by methods of reasoning one can evaluate. It is whether the methods pass muster that counts for or against a scientific opinion, not how the opinion fits our preconceptions.'"

You could have just used the obvious one:

"Official science is too much at ease with the Darwinian narrative--primarily because it can't come up with anything better. As a result, many scientists are driven by an ideological bias and by fear--the thought that any challenge to the narrative will plunge the republic back into some dark age."

Thanks for the link on new species! While I find the whole evolutionist/creationist battle tedious (Let's see them talk God out of evolution), the wonderful science that Darwinism has provoked never ceases to amaze me.